Airplane bracing



Nov. 17, 1936. G. LOENING AIRPLANE BRACING Filed Aug. 11, 1933 INVENTOR ATTORNEY Patented Nov. 17, 1936 UNHTEE STATES PATENT OFFICE AIRPLANE BRACIN G Application August 11,

3 Claims.

This invention relates to exposed solid wire bracing of airplanes, hydroplanes, and the like, and comprises a plurality of substantially parallel bracing elements closely associated and of crosssections which are complemental so that, together, they present the contour of substantially a single stream-line body. In this way, parasite resistance may be materially reduced and speed may be correspondingly increased.

The invention finds particular application in double bracing, each element of which is capable of sustaining the full load. For safety, wirebraced monoplanes may be provided with two tension members, or flying wires, beneath each half of the wing, either of these wires being capable of resisting the upward pressure on the wing. Any duplication of external bracing materially increases drag and subtracts from speed.

In the invention herein illustrated, the two flying wires are disposed immediately adjacent each other and are of such cross-sections that the combination forms a stream-line contour.

Preferably, the bracing elements are disposed in front and behind each other, with the division of the stream-line shape substantially vertical. A construction such as this has special advantages, among which is that flying wires of substantially equal cross-sectional area and therefore of substantially equal strength have different shapes, in consequence of which their periods of vibration differ, so that the vibration of each checks the vibration of the other, particularly if the wires are bound together.

Another object of the invention is to provide simple, reliable and convenient means for equalizing the relative tension of the wires, without disturbing their effective parallelism.

Other objects, features and advantages of the invention will be understood from the description contained in the following part of the specification and from the drawing of the preferred embodiment.

In the said drawing:

Fig. 1 is a fragmentary simplified front elevation of a wire-braced monoplane embodying the invention;

Fig. 2 is an enlarged sectional view on the line 2-2 of Fig. 1;

Fig. 3 is an enlarged plan view of the tensioning device shown in Fig. 1;

Fig. 4 is a front view of the tensioning device shown in Fig. 3; and

Fig. 5 is a sectional view taken on the line 55 of Fig. 3.

Fig. 1 shows a monoplane flying machine hav- 1933, Serial No. 684,611

ing a body If), wings l2, an enclosed engine mounting l4, and a propeller 16. Each wing is braced by a wire 18 connected with the engine mounting and extending outwardly and downwardly to a point of connection with the wing. The wires [8 brace the wings when the airplane alights or is on the water or land, and for this reason are termed landing wires.

Each wing I2 is braced to withstand the upward force encountered in flight by bracing means 20 comprising two tension members or flying wires 2! and 22, which connect with the lower part of the body If! and extend upwardly and outwardly to a connection with the wing.

The flying wires 2| and 22 are parallel and are located adjacent to one another, either in actual contact, as shown in Fig. 2, or near together. The wires 2| and 22 are shaped so that their combined contour is that of a single stream-line body, and the wires are preferably located one behind the other, as in Fig. 2.

In this embodiment, the front wire 2| has the shape of the front portion of a stream-line body, and the wire 22 has the tapering shape of the rear portion of a stream-line body. The shape of the two wires is therefore not the same, but they are of equal cross-sectional area so that they have substantially the same strength in tension.

When the tension on the wires 2! and 22 is substantially equal, the difference in the shapes of these wires makes their natural periods of vibration different. If the wires are in close contact, the friction between them will damp their respective vibrations, but preferably the wires are bound or tied together at one or more regions, as indicated at 24, so that any tendency of either to vibrate opposes the tendency of the other.

The wires 2| and 22 are connected with the body In, or with the wing, by a tensioning device 25, by which the relative loading of the two wires can be regulated. This tensioning device includes two links 3| and 32 connected with the ends of the wires 21 and 22, respectively. Both links 3| and 32 have a common pivotal connection 34, or coaxial connections, with the airplane hull or body H3.

The links 3! and 32 have clevis ends for receiving the flattened ends of the wires 21 and 22. A pin 36 connects the wire 22 with the link 32. The head of the pin 36 is countersunk so that it does not extend beyond the side of the link, and the adjacent link 3| prevents the pin 36 from sliding out of its link 32.

The wire 2! is connected with the link 3| by an eccentric pin 38, best shown in Fig. 5. This eccentric pin has a countersunk head 49 held in one side of the link 36 as a bearing, a cylindrical stem portion 42 which is eccentric with respect to the head 49, and a hexagonal end 44 extending from the stem portion 42. A bushing 46 turns in the link 3! as a bearing and is located on a common axis with the head 40. The bushing 46 has an eccentric hexagonal opening through which the end 44 of the pin 33 passes.

The hexagonal end 44 is drilled to receive a pin 48. A boss 50 on the side of the link 3| has openings 52 spaced around its circumference so that the pin 48 can be inserted through the boss 50 and pin 38 to hold the eccentric in position to obtain the desired tension of the wire 2|.

The tension of the wire 2| is regulated by removing the pin 48, applying a wrench to the hexagonal end of the eccentric pin 38, and turning this eccentric pin one way or the other to move the end of the wire 2| with respect to that of the wire 22 and thus change the relative tension of the wires. When the load between the two wires 2! and 22 is substantially equal, the pin 4 3 is inserted through the boss 56 and pin 38 to hold the eccentric in set position. There are enough of the openings 52 so that the tension of the wire 2! can be adjusted with substantial exactitude.

The links 3! and 32 comprise means for maintaining the adjacency and parallelism of the wires and 22 regardless of the position of the eccentric. The wire 22 is always in line with the pivot connection 34, and the link 3| moves on the pivot connection 34 whenever the eccentric is moved to change the tension of the wire 2!, the link 35 always occupying such a position that the wire 23 remains in line with the pivot connection 32 and therefore does not move out of its relation to the wire 22.

With means such as has been described for equalizing the tension of the flying wires, it is necessary to adjust the tension of only one wire of the pair. All rigging is preferably done with the landing wires.

For clearness of illustration, the tensioning devices are shown outside the body of the machine, but it will be understood that they may be absorbed within the lines of the body.

The preferred embodiment of the invention has been described, but changes and modifications may be made, and some features of the invention may be used alone or in combination with other features, without departing from the invention defined in the claims.

I claim:

1. In an airplane, a pair of solid wing-brace wires, parallel and adjacent and or" substantially equal strength, and of complemental crosssectional shapes forming a single stream-line contour, and means for adjusting the tension of one of said wires to equalize the tension on the two wires.

2. In a wire-braced airplane, a wing brace comprising two adjacent parallel wires shaped to the contour of a single stream-line body; means connecting opposite ends of the wires with the airplane body and wing including two links pivotally connected to the airplane for oscillation on a common axis, and a connection between each wire and one of the links, one of said connections comprising an eccentric which turns on an axis parallel to the pivotal axis of the links to regulate the relative tension of the two wires.

3. A double bracing for a Wing comprising two solid wires closely associated, one behind the other, said wires being of equal strength, but of different cross-sectional shapes so that their periods of vibration differ and the vibration of each checks the vibration of the other, and means for effecting relative adjustment of the tension of said wires.

GROVER LOENING. 

